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Smiley Re: Synthetic Time is being issued on Partition ...
hi,nachfolgend habe ich ein paar Auszüge aus den Novell Tid-files dazu kopiert.Man kann das aber mit meinen ersten Beitrag abkürzen.Wenn da was schief geht ... mußt du eben dein Backup vorher überprüfen ob du wirklich alles wieder herstellen kannst, im Fall der Fälle. Novell wird dir im übrigen nichts anderes Erzählen. Es wird immer Konfigurationen geben, bei denenReparaturversuche sich anders auswirken wie bei anderen.Ich kann hier nur berichten, das ich auf diese Art in knapp 10 Jahren min. 4x das Problem unter 4.11 und 5.1 so gelöst habe und sehe die Sache entspannter, dennwas wird schon dabei gemacht?Es werden die Zeitstempel neu gesetzt, Masterreplica neuen Status verpasst und eine Menge Netzwerktrafik erzeugt.Das ist vordergründig mal alles!Noch eine Anmerkung dazu: Dass alle restlichen Module abgeschalten,alle User und sonstige Dienste ausgeloggt sind ist ja hoffentlich selbstverständlich.___Synthetic Time Beitrag 1How do I fix synthetic time with DS Repair?This should only be done if time was set far into the future and it is not reasonable to wait for the problem to correct itself. Following these steps will cause the Master replica of the partition that synthetic time is issued upon to change all time stamps to current system time and change all other replicas in the replica ring to a "New Replica" state. The Master replica will then send out the new data (with the corrected time stamps) to all other replicas. This will generate a large amount of traffic if the partition is large or if there are a large number of servers in the replica ring. If the replica ring is large, remove some of the servers from the replica ring with Partition Manager before proceeding. Since all servers in the replica ring will simultaneously be attempting to receive all objects and transition to ON states, it is a good idea to have the replica ring as small as possible 3-5 replicas maximum, not including subordinate references. Once you are satisfied that your tree is healthy and the replica ring is sufficiently small, follow these steps.Before beginning, load dsrepair -rc on all servers holding a copy of the partition issuing synthetic time. This will create a backup of the DS database. 1. Make sure time is correct and in sync.2. Make sure the replica in question is synchronizing. ("All processed = Yes" from DSTRACE on all servers in the ring)2. Load DSREPAIR -A from any server in the replica ring.3. Choose "Advanced options menu".4. Choose "Replica and partition operations".5. Highlight the Partition indicating a synthetic time error and press Enter.6. Choose "Repair time stamps and declare a new epoch". (NOTE: This option will not show if -a switch not used)7. Login as Admin or Equivalent.EXTREME CAUTION should be used in executing this option. A large amount of traffic is associated with "Repair time stamps and declare a new epoch", and the servers that share in the replica should all be able to communicate with each other. (NO DSTRACE ERRORS!!!!) Depending upon the tree design, and number of replicas, the operation could take a long time. If at all possible, it is best to reduce the replica ring to a minimum amount of servers. Then place replicas back out on servers after this operation is completed. Consider performing this operation during non-production hours or during low traffic times.What if I don't know how for off my time was set?If you are not sure how for off the time was set you can find out with DS Repair.1. Load DS Repair from any server in the replica ring.2. Choose "Advanced options menu".3. Choose "Replica and partition operations".4. Highlight the Partition indicating a synthetic time error and press Enter.5. Choose "Display replica information".This will generate a log file. At the top of the log file is a section titled "Partition Information and Servers in the Replica Ring." There are several properties listed:___Synthetic Time Beitrag 2Fix One option to fix synthetic time is to just wait. If the synthetic time is not too far into the future, the problem will resolve itself. If the timestamp is more than a few days in the future, then you may need to declare a new epoch.Question: What is declare a new epoch doing?Answer: A new epoch causes the Master replica to re-set the modification time stamp of all objects in the partition and then send every object in that partition to all the other servers in the replica ring. All replicas except the Master will be put into a New state. This causes a lot of network traffic and can it take a long time for all the replicas to progress to an On state again. The speed of the links between servers and the number of servers in the replica ring will effect how long this process takes. Using DSRepair loaded with -a switch - Repair Time Stamps and Declare a New Epoch as described: CAUTION: DO NOT DO THIS UNTIL you have ensured that the master replica correctly reflects the actual state of the NDS AND that all the servers in the tree are communicating with each other AND there is no other partition operation pending). ALL OF THE ABOVE CONDITIONS MUST BE MET BEFORE YOU DO THIS!Load DSREPAIR -A | Advanced options menu | Replica and partition operations | select the partition of which this server holds the Master replica | Repair time stamps and declare new epoch. Note that this must be done on the Master of each partition that is reporting synthetic time.This option causes the Master replica to re-set the modification time stamp of all objects in the partition and then send every object in that partition to all the other servers in the replica ring. This option thus creates a lot of network traffic. You would only want to do this if the time difference is very large (e.g greater than 1 week) and you should do it either after business hours or during off-peak periods because of the high volume of network traffic. You must also ensure that your transport (LAN/WAN) is reliable, especially if you have replicas across WAN links. Make sure that the WAN links are not congested. You can verify the LAN/WAN links by doing a "Report Synchronization" in DSREPAIR. If you do not get any -625 errors, then the links are fine. The next question is then:How do I ensure that the master replica correctly reflects the actual state of the NDS?Login to the tree with the following username: {name of server holding Master replica}/{complete name of admin user} Use NDS Manager (WIN95& WINNT); Partition Manager (either in NWADMIN for Windows or in DOS) to make sure that the replica being read is the master replica. Then use NWADMIN or netadmin to browse through the tree. If NDS Manager or Partition Manager shows that the replica being read is NOT the master replica, then you can force the master replica to be read by locking the DS on all the servers with R/W replicas. To lock the DS, load DSREPAIR and do a "Repair local database on those servers". Do the above login while the other servers are performing the DSREPAIR.After declaring a new epoch on a partition, servers that do not hold a replica of that partition may still report future timestamps for objects in that partition. After you have declared a new epoch and all replicas are back to an On state, if you have a server that is reporting future timestamps for an object in that partition and it does not hold a Master, Read Write or Read Only copy of that partition, you will need to load DSREPAIR -xk3, go to the advanced options menu, and run a repair on the local DS database. Once the repair completes, save the repaired database and exit out of DSREPAIR. As soon as you have exited DSREPAIR, execute the following commands at the console prompt: SET DSTRACE=+BLINK and SET DSTRACE=*B. You can look at the DSTRACE screen to see the backlinks processing. There will be a message like "Finished Checking Backlinks Succeeded" when the backlink process finishes. You should then no longer see future timestamps on that server.___Synthetic Time Beitrag 3Problem: The NetWare® server reports the following error: Synthetic time is being issued on partition.Possible Cause: In NetWare 4 and later versions, synthetic time is issued at a server with the error DS- 4.63-12 if the server time is set backwards. The synthetic time is cycled every two minutes until the server time is later than the last modified time stamp.Action: Run DSREPAIR. Click Advanced Options > Replica and Partition Operations, and then select the partition you want to update.___Symptom Synthetic Time is being issued on Partition --------------------------------------------------------------------------------Cause There are problem with Timesync 5.15 that will allow timestamps to jump into the future as much 10 to 60 years. --------------------------------------------------------------------------------Fix In DSBrowse we searched for Attributes that had future timestamps. (Load Dsbrowse | Object Search| Complete Attribute Information, Name = *, Time Comparison = > Great Than and the current time, execute the search) The only object ahead in time was the partiton root object. One Server with a Sub Ref had a partition record that was ahead in time. We removed the parent from that server, then, in DSDump, removed the S/R. We were then able to timestamp the remaining partition entries on the other servers, also in DSDump, which resolve the synthetic time issue. This would not be practical if many objects showed the future time stamp.Deploy Timesync 5.20j or later to prevent reoccurrence.Grüße Andy



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